This paper presents an overview of several studies on teacher collaboration, then describes the process of developing recommendations for school leaders interested in encouraging collaboration. The five studies focused on: (1) collaboration and student learning outcomes; (2) the effect of selected factors on collaboration; (3) collaboration from the teacher's perspective; (4) whole school development through collaboration; and (5) leadership for pedagogical change. Developing the recommendations involved examining the data that resulted from each of the studies. The results identified six main areas that school leaders can address when fostering teacher collaboration. These areas include: (1) being thoughtful in recruiting and selecting staff; (2) carefully delineating work assignments and timetabling; (3) establishing collegial expectations among beginning teachers; (4) enabling across school collaboration; (5) providing opportunities for leadership for collaboration; and (6) establishing trust and clearly delineating supervisory and collaborative relations. (Contains 39 references.) (SM)